Insulator



June 10, 1924.

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June 10, 1924.

June 10, 1924..

A. O. AUSTIN INSULATOR 7 Sheets-Sheet '7 Filed Dec. 5, 1919 Patented June 10, 1924.

UNITED STATES PATENT OFFICE.

ARTHUR O. AUSTIN, 0F BARBERTON, OHIO, ASSIGNOR, BY MESIWE ASSIGNIEHTB, TO THE OHIO BRASS COMPANY, OF MANSFIELD, OHIO, A CORPORATION O! NEW JERSEY.

INBULATOR.

Application filed December 3, 1919. Serial No. 342,195.

To all whom it may concern:

Be it known that I, ARTHUR 0. A rman, a citizen of the United States, residing at Barberton, in the county of Summit and State of Ohio, have invented certain new and useful Improvements in Insulators, of which the following is a specification;

This invention has for its object the provision of a device of the class named which shall be of improved construction and operation.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawings and described in the following specification, and itis more articularly pointed out in the appended c aims.

In the drawings- Fig. 1 is an elevation of an insulator embodying one form of the present invention;

Fig. 2 is a view of one end of the insulator shown in Fig. 1 with parts in section;

Fig. 3 is a sectional view taken atright angles to the section shown in Fig. 2; I

Fig. t is a transverse section on line 4-4 of Flg. 3;

Fig. 5 is a sectional view of one end of an insulator showing a modified form of the invention;

Fig. 6 is a view of the end of the stress member shown in Fig. 5 looking at right angles to the view in that fi ure;

Fig. 7 is a section througi the end of an insulator showing another modification;

Fig. 8 is a section on line 8-8 of Fi 7;

Fig. 9 is a section through the end 0 another modification; I

Fig. 10 is a section on line 10-10 of Fig. 9;

Fig. 11 is a section through the end of another modification.

The embodiment of the invention shown in Figs. 1 to 4 of the drawings comprises a tube or shell 10 of insulating material, such as porcelain, provided with suitable flanges or petticoats 11. The tube may be made in sections united by connecting members 12,

or if desired, it may be made in a continuous piece. The strain of the load supported by the insulator is carried not by the tube 10, but by internal stress members 13. The members 13 are preferably slotted at their ends. as shown at 14, to provide frictional bearing faces and have their outer surfaces beveled, as shown at 15. The beveled surfaces 15 provide a wedge-shaped head which is clamped between holding plates 16 and 17.

'cap or housing 19 which is provided with a series of projecting webs 20 to which the holding plates 16 and 17 are secured by bolts 21. The housin 19 is tap ed to receive the threaded en s of the b0 ts 21 and one side of the housing is provided with a removable cover 22, Fig. 1, to permit placing the lates 16 and 17 and the bolts 21 in place. t will be seen from Fi 4 that the holdin plates 16 do not bear irectly u on the we 20,, thus leaving the bolts 21 ree to clamp the stress members 13 between the inner faces of the plates16. The webs 20, as shown in Fig. 2, do not extend the full length of the plates 16 and additional bolts 23 extend through the plates to assist in clamping them a ainst the faces of the stress members. The orce exerted by the members 13 is transmitted to the inclined faces of the holding plates 16 and 17 and to the frictional faces of the plates 18 and from these plates to the bolts 21 and the webs 20 carried by the housing 19.' Since the two stress members 13 are both clamped in the same set of plates it will be apparent that the plates will act to e ualize the stress in the two members, for if the stress becomes greater in one member than in the other, this member will be drawn between v the wedging faces of the plates until the stress is equalized. The holding plates and securing bolts are the same at each end of the insulator, with the exception that the portion of the housing 19 into which the bolts 21 are threaded is turned at 180 degrees from the corresponding part of thehousing at the opposite end of the insulator. 'The reason for this difference in position is to neutralize any effect that might be produced on the stress members 13 by direct bearing of the bolts in the housing 19-. By the arrangement shown each stress member 13 is adjacent one of the direct screw-threaded .connections between the bolts 21 and the housing, the connection being adjacent one of the stress members at one end of the insula tor and adjacent the other stress member at the opposite end of the insulator.

The interior of the insulator is preferably filled with a semi-solid insulating compound and the cover plate 22 for the opening in. the housing 19 is provided with an expansion chamber 24 to take care of variations in the volume of the compound due to contraction and expansion. A breather 25 is provided to permit circulation of air between the interior of the expansion chamber and the outer atmosphere. The insulator is installed with the breather 25 above the level of the compound so that the compound will not leak out through the breather. As stated, the members 13 carry the load and the tubular member 10 is provided with a connection with the housing 19 which is sufliciently tight to retain the compound within the insulator and to exclude moisture, but permits sliding movement between the tube '10 and the housing 19. This connection comprises a sleeve 26 bolted to a flange 26 on the housing 19. The end of the tube 10 extends into the sleeve 26 and is provided with a surroundin layer 27 of resilient material, such as cor The layer of material 27 may be held in place on the end of the tube 10 by a wrapping of wire 28. A layer of cement 29 is interposed between the sleeve 26 and the wire wrapping 28 for holding the cork and wire in place in the sleeve. In this way a packed joint is provided between the end of the tube 10 and the housing 19 which is sufliciently tight to exclude moisture but will permit of sufficient movement between the tube and the housing to insure that the force of the load will be taken by the members 13. The members 13 are made of material, such as wood. which has relatively high tensile strength and which is a dielectric when kept dr The form of the invention shown in Figs. 5 and 6 is adapted to relatively large sized insulators. In this forma connecting bar 30 is provided with a holding block 31 in which dove tailed grooves 32 are formed. A series of plates 33 are provided with tongues 34 to fit into grooves 32. The plates have their faces inclined as shown to give them a wedge shape. Tension members 35 have their ends arranged between the plates 33 and the plates and tension'members are clamped together by bolts 36. The openings for the bolts 36 in the tension members 35 are large enough to permit movement of tension members so that the members are other forms of the invention the tapered contact heads prevent the tension members from being released in case of shrin'ka e for the members will be automatical y tightened as the load draws the wedge shaped heads between their holding members.

By properly proportioning the friction area to the cross section of the tension members it is possible to regulate the slippage of the tension members under the load so as to equalize the load or to properly distribute the load between the members according to their cross sectional area. Unless the parts are arranged so that the grip is increased by slippage it would be necessary to ti hten the members so that the maximum loa will not cause slippage. In this case one of the members may be caused to carry more load than the others owing to being clamped up short. It 'will be apparent that any number of members may be clamped together to provide insulators of any desired working tension.

It is evident that where wedge shaped plates 37 are used the ends and body portions of the tension members need be no larger than the minimum section. Consequently the opening in the insulating sleeve surrounding the tension members can be made smaller. This sleeve in the form shown in Figs. 5 and 6 is shown as built up of a plura ity of sections 38 cemented together at 39. Since the tension of the load is not carried by the inclosing sleeve these cement joints will not be subjected to wvere mechanical strains. The end sections 38 are cemented at 40 to end caps 41 which have sliding connection with the tension member 30 by means of a stufling box 42.

In the form of the invention shown in Figs. 7 and 8 the stress members 42 and 43 differ from one' another in cross section so that they will conform more closely when assembled to the circular sleeve in which they are laced. The total cross sectional area of t e various members may be the holding block 44 secured to its outer face by.

a pin 45. Friction plates 46 are interposed between the tension members and have ears 47 engaging a shoulder 48 on the end member 49. The inner face of the end member 49 is tapered to fit the outer faces of the wedge members 44 so that if the stress mem-. bers slip under the load the wedge members will tighten the frictional grip until the slippingeis arrested. If any one of the inner mem rs 43 slips a greater force is permitted to come upon the outer members I of the invention it is usual to put the parts 7 members 44 tightly in turns of conductor together with a comparative small amount of clamping pressure and then subject them to a load to cause them to be properly positioned in the clamping members. A greater clamping force may then be applied to the clamping friction members. In this form shown in Figs. 7 and 8 a separable cover plate closes the end of the member 49 andscrews 51 are provided for forcin the wedge lace. he tension members may be inserte through the opening, closedby the cover plate 50 or they may be inserted individually from the other side of the member 49, the outer tension members being inserted first and moved outwardly to permit the insertion of the central members, after which the assembled parts are wedged into lace.

The insulator s eeve 52 is connected by a sliding joint to the end member 49 in a manner similar to that described in Figs. 1 to 4. It may be advisable to wind a few about the insulator sleeve 52 and connect them by a jumper 53 with the end member 49. This will prevent leakage or charging currents from traversing the joint between the end member and insulator sleeve. Current in this joint would char the cork and otherwise injure the joint. A connection 54 with the interior of the insulator sleeve is provided to which an expansion chamber for insulating filler for the interior of the sleeve may be attached.

Charging currents or any discharge in insulators having an external protecting sleeve of the kind described in connection with this invention should occur over the outer shell and not through the inner stress members. This will protect the stress members from charring or other injurious effects of such currents. A filling of insulating compound or oil within the shell assists in forcing discharge or leakage over the outer shell. This is particularly true where insulating flanges are added to the main body. Any moisture from the weather conditions that might give rise to discharges will occur on the shell and not on the stress members.

In the form of the invention shown in Figs. 9 and 10 a central stress member 55 is employed to which is secured a plurality of wedge-shaped friction holding members 56. A tapered end member 57 is shaped to receive the wedges 56 and provide friction bearing surface therefor. A closing. cap 58 is threaded into the member 57 and bears on the outer ends of the wedges 56 to hold them 1n place. Each wedge 56 bears frictionally upon the tension rod 55 to grip the rod, and a screw 59 is threaded through each wedge into the rod to insure that any slipping that takes place, occurs between the incllned surfaces to tighten the grip rather than between the rod and wedges. The insulator shell 60 is held to the end member 57 by a sliding joint similar to that of the forms previously described.

In the form of the invention shown in Fig. 11 the stress member 61 is in the form of a hollow tube. The tube may be made up of layers, as shown, to facilitate spreading of the end, and such spreading may be further facilitated by lon itudinal slits at the end thereof. A cone-s aped member is inser ted in the end of the tube after the tube 1s in place in the end member 63, and the tube is thus flared outwardly to contact with the ta ered opening in the end member. After 1t has thus been flared a screw 64 may be inserted throu h an opening in the member 63 and threafed into the cone 62 to prevent slipping between the tube and cone. The opening in the member 63 may then be closed with a plug 65. It will be seen that $11 page of the tension member 61 will tig ten the frictional grip on the walls of the tube by the tapered inner walls of the end member. 'A plug 66 closes the end of the member 63 and bears against the cone 62 to hold it in place. The cover shell 67 is attached to the end member 63 by a sliding joint as described in connection with the other forms. It will be seen that this cover member may be but very little larger than the stress member itself since the flared ortion of the stress member does not 11 pass through the shell nor through the opening in the end member adjacent the shell, but is flared out after it is in place.

I claim:

-1. An insulator comprising a holding member, a stress member connected with said holding member for carrying the load of said insulator, a casing of dielectric material surroundin said stress member, and a joint between said holding member and said casing, said joint being packed to permit of relative movement of. said holding member and casing and to exclude moisture from the interior of said casing.

2. An insulator comprising a holdin member, a pair of stress members attache to said holding member separately from one another, and frictionally yieldabl means for securing said stress members to said holding member to permit of equalization of the stresses between said stress members.

loo

3. An insulator comprising a holding member, a plurality of stress members attached to said holding'member separately from one another, and a clamping device for frictionally engaging said stress members to secure said stress members to said holding member, said ,clamping device being arranged to exert equal clamping force on each of said stress members.

4. An insulator comprising a holdingmember, a pair of stress members, clamping plates for engaging the ends of said stress members. and means for securing said clamping plates to said holding member and for exerting uniform pressure upon each of said stress members.

5. An insulator comprising a holdin mem ber. clamping plates connected with sai holding member, stress members having dovetailed ends interposed between sai clamping plates, and means for holding said clamping plates in engagement wlth the dovetailed ends of said stress members to produce uniform frictional engagement between said stressmembers and said clamping plates. v

6. In an insulator, a holding member, a stress member having the end thereof bifurcated to provide frictional surfaces. a friction plate interposed between the bifurcations of said stress member, and clamping plates arranged to engage the outer faces of said stress member and to press said bifurcations into frictional contact with said friction plate. I

7. An insulator comprising a holding member, a plurality of internal wooden stress members connected with said holding member for receiving the load upon said insulator, means for equalizing the stress between said stress members. a casing surrounding said stress members for protecting said members, and a packed joint between said casing and said holding member to permit of relative movement between said members while maintaining a close joint therebetween.

8. An insulator comprising a pair of relatively movable members and a packed joint between said members, said joint comprising a layer of resilient material engaging one of said members and wrapped so as to be held in place thereon, said layer of resilient material and the wrapping therefor being secured to the other of said members by cement.

9. An insulator comprising a holdin member, an internal stress member secure to said holding member for carrying the load upon said insulator, a casing of vitreous material surrounding said stress member, a packed joint between said casing and holding member comprising a layer of resilient material on said casing and secured thereto by a wrapping of wire, a sleeve surrounding the wrapped (portion of said casing, and cement interpose between said sleeve and said wire wrapping.

10. An insulator comprising a holdin member, stress members secured to sai holding member, a plurality of wedge for securing said stress members to said holding members, said securing means being non-symmetrical relative to said stress members and said holding means being arranged in different positions relative to the stress members at the opposite ends thereof to compensate for the non-symmetry of said securing means;

12. An insulator comprising a pair of end caps, a plurality of stress members connected to said end caps, and bolts for bold ing said stress members to said end caps, said bolts each having one end directly connected to one of said end caps at one side thereof, the sides of said end caps to which said bolts are directly connected being arranged at 180 degrees from one another.

13. In combination, a holding member and a plurality of stress members each secured to said holding member separately from the others, and a'yielding connection for securing said holding member to said stress members so that the connection with said members will yield under excess load on any one of said stress members to equalize the load on said members.

14. In combination a holding member a plurality of stress members each secured to said holding member by a yielding connection to permit individual yielding of said stress members under load to equalize the load on said members and means for automatically tightening the connection between said holding members and said stress members when yielding under load occurs.

15. In combinationa stress member, means having frictional engagement with said stress member for holding the same and to permit slippage thereof under excess load and means for automatically tightening the,

engagement between said stress member and holding means when slippage occurs.

16. In combination a plurality of stress members, means having frictional engagement with said members for holding the same, and arranged to permit slippa e of said stress members independently of one another to equalize stresses between said members, and means for automatically tightening the holding force on said members when slippage occurs.

17. In combination, a holding member, a stress member secured to said holding member, a yielding connection between said stress member and said holding member to permit holding member to permit said stress mem-' bers to yield under excess load to secure equalization of the load among said stress members, and a protecting shield surrounding said stress members and having movable connection with said holding member to prevent the stress of the load from coming on said shield.

19. In combination, a holding member, a stress member secured to said holding member, a yielding joint between said stress member and said holding member that will permit slipping under excess load, means for automatically tightening said joint when slippage occurs, and a casing surrounding saidstress member and having yielding connection with said holding member to permit of relative movement of said stress member and holding member without imparting stress to said casing.

20. In combination, a holding member, a plurality of stress'members, wedging frictional connections between said holding member and said stressmembers to permit individual slippage of said stress members to equalize the load thereamong and to automatically tighten the connection between said holding member. and said stress mem bers when said slippage occurs, and a sleeve surrounding said stress member having slid ing connection with said holding member to prevent transmission of stress to said sleeve.

21. In combination, a pluralityof stress members, means for holding said stress members to permit slippage thereof to equalize the load, a casing surrounding said stress members, an insulating filler within said casing, and an'expansion chamber and breather to provide for'flow of said filler into and out of said casing.

22. An insulator comprising a holding member, a plurality of stress members of fibrous material, said stress members having frictional surfaces contacting with said holding member, the contact surfaces being inclined to produce a wedging action under the stress of the load on said members, and a substantially impervious housing for said stress members.

23. An insulator comprising a holding member, a plurality of stress members; and friction plates having inclined faces for engaging correspondingly inclined faces on said stress members, one of said plates being interposed between two of said stress members so that pressure produced by the wedging action of one of said stress members will be transmitted to the other.

24. An insulator comprising a holding member, a plurality of stress members having wedge-shaped connecting portions. holding plates for engaging said wedge-shaped portions, and clamping means for exertln common pressure on a plurality of said plates and stress members so that force exerted by yielding movement of one of said stress members under load will be transmitted to the otherof said stress members to automatically tighten the grip on said other member.

25. An insulator com rising a holding member, a plurality of olding plates secured to said holding member, a lurality of stress members having wedge-s aped ends interposed between said holding plates, said stress members having slots therein, friction plates disposed in said slots, a common clamping device for said plates and stress members to exert uniform pressure on all of said stress members, a substantially impervious housing surroundin said stress members, and a yielding pac ed joint between said holding member and said housing to permit movement of said holding member relative to said housing.

In testimony whereof I have signed my name to this specification on this 31st day of October A. D. 1919.

ARTHUR O. AUSTIN. 

